This invention relates to a heat regenerator and more particularly to a heat regenerator of the type arranged between the expansion space and compression space of a heat gas engine such as a stirling cycle engine to effect thermal regeneration.
To operate a regenerator at a high performance, it is required not only that the materials to be used have a high thermal capacity but also that the regenerator have a large specific surface area, namely a large heat transfer or conductive surface area per unit volume, a smaller dead volume internally of the regenerator, and little fluidic resistance. For this purpose, Book B, Vol. 248, No. 435 of the technical papers of the Japan Mechanics Society (November, 1982) describes a regenerator structure comprising a cylindrical body and a number of wire mesh screens stacked in the cylindrical body and consisting of wires made of copper or SUS-27.
With the wire mesh screens used in a conventional regenerator, thermal capacity, specific surface area, dead volume and fluidic resistance naturally are decided by the number of stacks of wire mesh screens in the regenerator, the wire mesh material, the number of meshes and the wire diameter. To increase thermal capacity and specific surface area, therefore, one possible approach is to enlarge the size of the wire mesh screens and increase the number of stacks thereof, and another is to reduce wire diameter and increase the number of meshes. However, the former increases dead volume, and the latter raises fluidic resistance by decreasing the degree of pore opening of the meshes. The end result in either case is a failure to improve regenerator performance.